Guest

I've assembled and soldered circuit and have checked and all components appear to be correct, however when powered the LED and buzzer go on, as manual states, however turning VR1 does nothing. LED and buzzer remain on.

Guest

Hi, I am experiencing the same problem with my metal detector kit as vin. The metal detector keeps buzzing and the LED remains on with no change no matter how I try to turn the VR1 potentiometer. Bring any metal near the induction loop does not change the tone or the loudness of the buzzer. I have checked the copper wire connections between the loop and the board with the multimeter and all the components values and placement, which are correct. The only possible explaination why the kit does not work is due to a flawed circuit. Any ideas on what could have gone wrong with the metal detector kit?